561
FXUS66 KLOX 192103
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
203 PM PDT Fri Jul 19 2024

.SYNOPSIS...19/105 PM.

Well above normal temperatures are expected through early next
week, especially the interior areas, though some cooling is
expected closer to the coast as onshore flow increases. Night and
morning low clouds and areas of dense fog will continue near the
coast.

&&

.SHORT TERM (TDY-MON)...19/143 PM.

After a cooler start this morning courtesy of dryer air over
the area, temperatures have rebounded quite well with most
coast/valley areas up 3-6 degrees from yesterday and some of the
lower mountain areas up 12 from yesterday.

Strong high pressure across the western states is still
generating well above normal temperatures across the region, but
especially across the far interior where highs approaching 110 are
possible each day through the middle of next week. However,
closer to the coast and including the some of the valleys a 1200`
marine layer and roughly a 3mb onshore flow is providing a
moderating effect on the temperatures, keeping highs mostly in the
80s and 90s, except some very low 100s across the western San
Fernando Valley, Santa Clarita Valley, and in the southern
Salinas Valley. In addition, there have been ample overnight
recoveries in those areas with lows mostly in the 60s and even
some high 50s. So heat risk in those areas, especially factoring
in the relatively cool overnight temperatures, while not zero, are
not quite reaching criteria for advisories and warnings. Some of
the higher elevations above the valleys, such as the Santa Monica
Mountains above 2000 feet, where overnight lows haven`t dropped
much below 80, heat risk factors are much higher and advisories
continue through at least Sunday.

Minimal, if any, changes are expected in this pattern through
early next week. There will be slight warming across the far
interior, but closer to the coast very little change. A shallow
marine layer will keep a chance of low visibilities near the
coast during the night and morning hours.

.LONG TERM (TUE-FRI)...19/156 PM.

No significant changes in temperatures early next week so it will
remain dangerously hot across the far interior, and 4-8 degrees
normal elsewhere. Ensemble based guidance indicates slight warming
may develop Tuesday and Wednesday away from the immediate coast
which may push some areas into heat advisory territory,
particularly across the southern Salinas Valley and warmer parts
of the LA/Ventura Valleys. Then as high pressure begins to weaken
Thursday and Friday highs in all areas are expected to cool with
those trends continuing into next weekend.

Lastly, increasing moisture from the southeast east next Tuesday
and Wednesday may be enough to bring some thunderstorms back to
at least eastern LA County. Otherwise, thunderstorm chances will
be under 10% through the period.

&&

.AVIATION...19/1553Z.

At 15Z over KLAX, the marine layer was 1200 feet deep. The top of
the inversion was at 4000 feet with a temperature of 28 Celsius.

High confidence in VFR and minimal concerns through Saturday for
KPRB KBUR KVNY KWJF KPMD.

All other sites, moderate confidence in any ceilings and
visibility being low (LIFR/IFR), low confidence on timing (+/- 6
hours). There is a 30 percent chance in less than 3 hours of VFR
conditions today at KOXR.

KLAX...Moderate confidence of improvement to VFR occurring as
early as 17Z and as late as 19Z. Low clouds could hug the beaches
for most of the day, which would result in 5-8SM HZ at the airport
lingering into the afternoon. Ceilings will return as early as
00Z and as late as 08Z (low confidence on timing). Moderate
confidence in IFR conditions most common, with brief LIFR. High
confidence in any east winds staying under 6 knots.

KBUR...High confidence in VFR conditions through Saturday with
seasonal winds.

&&

.MARINE...19/853 AM.

Moderate confidence in dense fog and visibilities under one mile
being an issue today and likely through early next week,
especially north of Point Mugu and the Channel Islands. The
reduced visibilities will likely linger well into the afternoon
hours.

High confidence in northwest winds increasing each day through
Saturday or Sunday. High confidence in at least Small Craft
Advisory (SCA) winds and steep seas for the outer waters (offshore
from the Central Coast to San Nicolas Island) by this afternoon
and lasting through Sunday or Monday night. 70 percent chance of
reaching Gales Saturday evening through Sunday evening. Will
likely be converting the Gale Watches to Warnings with the
afternoon update.

For the nearshore Central Coast waters, there is a 10 percent
chance of SCA conditions this afternoon and evening, increasing to
a 60 percent chance for Saturday and Sunday. Decided to delay the
Small Craft Advisory start from this afternoon to Saturday
afternoon as a result.

For the Santa Barbara Channel, fairly high confidence that SCA
winds and seas will stay very localized to the far western
portions today and tonight. The winds and steep seas will expand
Saturday and Sunday, with a 40 percent chance of those conditions
being widespread enough to warrant a Small Craft Advisory.
Decided to delay the Small Craft Advisory start from this
afternoon to Saturday afternoon as a result.

For the rest of the nearshore waters, choppy seas will be building
due to the gusty winds in the region, but SCA conditions are
unlikely.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning remains in effect until 10 PM PDT
      Wednesday for zones 38-344-345-353-376>383. (See LAXNPWLOX).
     Heat Advisory now in effect until 10 PM PDT Sunday for zones
      342-343-369-370-375. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect from 2 PM Saturday to 3 AM PDT
      Sunday for zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 2 PM PDT Saturday for
      zones 670-673-676. (See LAXMWWLOX).
     Gale Watch in effect from Saturday afternoon through Sunday
      evening for zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...Kittell
MARINE...Kittell
SYNOPSIS...MW

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox